The role and influence of various elements in aluminium alloy die casting:
Silicon: The main element in aluminium alloys, which can improve the casting properties of alloys. Silicon and aluminium can form solid melts.
Magnesium: It can improve strength and yield limit, cutting machinability and corrosion resistance.
Zinc: Zinc can improve fluidity, increase hot brittleness and reduce corrosion resistance.
Iron: When the iron content is less than 6%, the adhesion force of the die can be reduced.
Manganese: Manganese in aluminium alloy can reduce the harmful effect of iron, change iron sheet into needle-like sheet, into fine-grained structure, 5% is medium.
Nickel: It improves strength and hardness, reduces corrosion resistance, and has the same effect as iron.
Titanium: It can refine grain structure, improve mechanical properties and reduce hot cracking tendency of alloy.
If the die casting die can not be discharged smoothly in the work, the injection speed of the die casting machine can reach the speed of the warhead. In such a rapid filling process, the air in the cavity must be expelled rapidly. Otherwise, it will cause various problems of aluminium alloy die castings.
1. The blocked gas forms high pressure in the cavity, and seeps into liquid metal under certain degree of compression, resulting in quality defects such as voids, stomata, cracks and loose tissue.
2. The poor degassing makes the melting speed of each cavity different, and it is easy to form melt marks and flow marks, which reduces the mechanical properties of aluminium alloy die castings.
Three. The gas barrier in the receiving chamber will reduce the filling speed, affect the forming cycle and reduce the production efficiency.
4. The high compression of gas causes the temperature of the cavity to rise rapidly, which leads to the melt combustion decomposition around the cavity, resulting in local combustion and carbonization of aluminum alloy die castings.
5. In the pouring process, melt replaces the gas in the cavity. If the gas is not removed in time, it will be difficult to fill the melt, resulting in insufficient injection and cavity filling.
Solutions to the Advantages of Zinc Alloy Die Casting
1. Zinc alloy die castings are widely used in large-scale and full-scale die casting.
2. According to the characteristics of aluminium alloy itself, it is not difficult to know that the white appearance lubricity of die casting products is very strong, and the important thing is that the dimensional accuracy is also very high.
Three. Because of its simple and convenient operation, the consumption rate is still very high.
4. This method has a high application rate to metals and prevents the waste of resources.
5. By this way, the die-casting products have high hardness and strength, are not easy to fracture, and are very durable.
3. Moderate polishing. Contours cannot be highly polished. Appropriate polishing methods should be adopted.
4. Oxidation treatment. The surface of die casting die should be oxidized.
5. Preheat correctly. Die casting die should be preheated to appropriate temperature by correct method.
6. Moderate cooling. In order to ensure proper cooling of the die-casting die, the cooling water temperature should be kept at 40-50 degrees Celsius.
7. Reasonable use. If temporary shutdown is required, cooling water should be reduced to avoid thermal shock of die casting die during start-up.
The above is the correct way to use the die casting die. As long as attention is paid before use and maintenance after use, the service life of die casting die can be prolonged and greater value can be created.